Algebra word problems: miles per gallon

In a family there are two cars. In a given week, the first car gets an average of 25 miles per gallon, and the second car gets 40 miles per gallon. The two cars combined drive a total of 2100 miles in that week, for a total gas consumption of 60 gallons. How many gallons were consumed by each of the two cars that week?

Solution Preview

Suppose the first car consumed x gallons, the second car consumed y ...